Description of Empathy::Reading People (page 129) states:
This is an assessment (page 115) action and, as such, if you gain one or more shifts on your roll, you discover one of the target’s aspects that you weren’t already aware of.
However, from what I can see reading the Assessment description, there is no mention about shifts. Yet, Reading People wording (see the bolded part) implies, that the description on page 115 states the same fact: Assessment reveals an Aspect only when you get one or more shifts (which it obviously doesn't).
So I ask - do assessments require shifts to reveal aspects or not? Can you please back up your answer with quotes from or page numbers in the Your Story book or the official fate blog?